Infrared Studies of Circumstellar Dust in Planet-Forming Exo-Systems

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Dr. Carey Lisse of Johns Hopkins University will investigate the formation and evolution of asteroids, comets, and planetary bodies around young stars. The research will compare mid-infrared observations of dust in circumstellar disks to planetary astronomy studies of solar system comets, interplanetary dust, and meteorites. He will focus on determining the location, amount, and mineralogical and elemental composition of the material (including water ice and polycyclic aromatic hydrocarbons) to infer the composition, location, and minimum mass of the parent bodies producing the dust. The goal is to obtain an understanding of the evolutionary processes in these young solar systems, and to determine parameters that will aid in the creation of better models of solar system formation. Included in the list of new spectra are a 1 million year old system with a spectral signature like that of comets; a system at the right age for terrestrial planet formation; one showing spectral signatures of hypervelocity impacts like the ones that formed the Moon or stripped Mercury of its surface layers; and a 'mature' system with very primitive dust like that in the interstellar medium, suggesting that the high temperature processing and radial mixing did not occur there. Dr. Lisse will also incorporate results from the Herschel Space Telescope to improve models of cold, icy dust in the outer parts of disk, while preparing the way for resolved spectral imaging of these and other systems by the James Webb Space Telescope mission in the next decade. Connections will be made with ground based optical/infra-red imagery from large telescopes and the upcoming Atacama Large Millimeter Array observatory. These new datasets will help constrain the location of the circumstellar material, improving the determination of the dust composition and mass, the taxonomy of the parent bodies, and the physical processes operating on the dust.